MANOJ CHANDRA RAO A/L RAMA RAO ME DHINESHKARAN A/L BALKARAN ME MITHIRAN A/L GENESEN ME PIVINESH NAIR A/L SREETHARAN NAIR ME YOGERAJA SAGARAN ME INTRODUCTION TO NUCLEAR TECHNOLOGY (MEHB 513) GROUP ASSIGNMENT

INTRODUCTION The earthquake on March 11, 2011, off the east coast of Honshu, Japan’s largest island, reportedly caused an automatic shutdown of 11 of Japan’s 55 operating nuclear power plants The Fukushima Daiichi plant subsequently suffered hydrogen explosions and severe nuclear fuel damage, releasing significant amounts of radioactive material into the environment Of course, ensuring the safety of nuclear power requires that safety management at nuclear plants be combined with nuclear security measures However, there were certain factors behind the accident at Fukushima that might have been prevented had greater consideration been paid to nuclear security in advance

SPECIFIC SAFETY MEASURES Installation of Vents Equipped with Filters on Reactors’ Containments Construction of Separate Earthquake Resistant Main Buildings as Emergency-Control Centres Introduction for Safety Reasons of a 40-Year Limit on Operation of Nuclear Power Plants Determination of Nuclear Plants’ Restart Following Stress Tests

REACTOR DESIGNS designed to produce low-carbon electricity at stable and competitive costs, constitute an element of the solution to global warming and a means of delivering power to emerging and developed countries needed to meet future energy demand the Generation IV International Forum (GIF) was created in January 2000 by 9 countries GIF defined in its Technology Roadmap 3 four goal areas to advance nuclear energy into its next, “fourth” generation : Sustainability; Safety and reliability; Economic competitiveness; Proliferation resistance and physical protection

Technology Roadmap 3 for the deployment of the Generation IV energy systems Generation IV nuclear energy systems include the nuclear reactor and its energy conversion systems, as well as the necessary fuel cycle technologies Fissile material, can be recovered from the spent fuel and used to make new fuel. At present, almost 95% of the spent fuel from light water reactors can be reused in the form of reprocessed uranium and MOX fuel. The advanced separation technologies for Generation IV systems are being designed to avoid the separation of sensitive materials, and they include other features to enhance proliferation resistance and incorporate effective safeguards

In 2002, GIF selected six systems from nearly 100 concepts as generation IV technologies This is done to focus on the most relevant developments of the six Generation IV systems selected, providing a high-level report that summarises the achievements of the past ten years and defines R&D goals for the next decade. Among those selected 6 systems are : Gas-cooled fast reactor (GFR); Lead-cooled fast reactor (LFR); Molten salt reactor (MSR); Sodium-cooled fast reactor (SFR); Supercritical-water-cooled reactor (SCWR); Very-high-temperature reactor (VHTR).

IMPACTS OF THE FUKUSHIMA NUCLEAR ACCIDENT ON THE TECHNOLOGY DEVELOPMENT OF NEW NUCLEAR PLANTS. 1. Energy Availability for Japan Needs. 2.Post Fukushima Impact towards New Nuclear Plant 3. Decline in operating capacity 4.Tsunami defences 5. Stress Tests Nuclear plant restarts 7. Further proposed plants 8. Post-construction modifications

SAFETY OF PLANT AND MITIGATION OF NUCLEAR ACCIDENT A rush to restart some of the country’s 48 mothballed commercial nuclear reactors is well under way Hundreds of technicians from utility firms are camped out in downmarket Tokyo hotels, working at the beck and call of the Nuclear Regulation Authority (NRA), the country’s new nuclear watchdog, in hopes of meeting new safety requirements 1. Pursuing Safety Improvements 2. Nuclear Regulation Authority (NRA) 3. Measures to Reinforce Safety, etc. for Nuclear Power Station Safety enhancement measures - Measures against tsunami, ensuring power sources, etc. (May 2011) Measures against tsunami Ensuring power sources Ensuring ultimate heat removal functions Measures for response to severe accidents (July 2011) Additional safety enhancement measures based on proposals by Aomori Prefecture (December 2011)

MAIN ISSUES TO BE HIGHLIGHTED Japan needs to import about 84% of its energy requirements. Its first commercial nuclear power reactor began operating in mid-1966, and nuclear energy has been a national strategic priority since This came under review following the 2011 Fukushima accident but has been confirmed. The country's 50+ main reactors have provided some 30% of the country's electricity and this was expected to increase to at least 40% by The prospect now is for at least half of this, from a depleted fleet of no more than 48 reactors. Japan has a full fuel cycle set-up, including enrichment and reprocessing of used fuel for recycle. The process of regulatory clearance for restarting 48 reactors is under way, but slowly and expected to take some years. Japan has been a leading country in nuclear R&D, notably with fast reactors. Following the Fukushima accident its regulatory structure was completely overhauled.

SAFETY VIEW ASPECTS From the outset, there has been a strong awareness of the potential hazard of both nuclear criticality and release of radioactive materials from generating electricity with nuclear power. As in other industries, the design and operation of nuclear power plants aims to minimise the likelihood of accidents, and avoid major human consequences when they occur. There have been three major reactor accidents in the history of civil nuclear power - Three Mile Island, Chernobyl and Fukushima. One was contained without harm to anyone, the next involved an intense fire without provision for containment, and the third severely tested the containment, allowing some release of radioactivity. These are the only major accidents to have occurred in over 15,000 cumulative reactor- years of commercial nuclear power operation in 33 countries. The evidence over six decades shows that nuclear power is a safe means of generating electricity. The risk of accidents in nuclear power plants is low and declining. The consequences of an accident or terrorist attack are minimal compared with other commonly accepted risks. Radiological effects on people of any radioactive releases can be avoided.